Yahoo! PlaceFinder is a REST web service that will turn an address into the latitudinal and longitudinal coordinates in XML, JSON, or serialized PHP objects. It has a few other functions too, like finding the nearest airport, time zone, and even telephone area code. [...] PlaceFinder is a very simple REST service, so cURL is a quick and easy way to access it. There are no authentication tokens to deal with or logon procedures. Just send a GET request, and read the response.

He links you to the service to get an API key and includes a simple class (PlaceFinderAPI) that builds the GET query for you and makes the request via curl. Also included is an example showing how to find a given location (coincidentally, his location choice is the hotel where the php|tek conferences are held).

One of the key features which was required for Emitter.ca, was the ability to geocode search terms like street addresses, cities, and postal codes, that a user enters so that Emitter.ca could easily return facilities that are nearby. To do this, we leveraged Bing Maps's API for performing the Geocode lookup. Microsoft offers a variety of APIs for allowing your application to interact with Bing Maps, however, for Geocoding search terms, we utilized Bing's SOAP API.

He shares the class he uses to pull the information out of the Bing Maps SOAP response and push the details into the properties of a class. The simpel class made interfacing with the API an easy task and allowed for string-based lookups on just about anywhere (like "Toronto, Ontario").

Geocoding is the process of finding the longitude and latitude of a given address or location. The Google Maps service gives developers and web site owners free access to their geocoder, both using the Google Maps JavaScript API, as well as using the web service. In this article I will show you how to access the geocoder web service using PHP so that it can be used in your own applications.

The tutorial walks you through every step of the way - from getting your Google API ID to making a simple request all the way out to using placemarks to store locations to fetch later on.

This is a great, very detailed summary that anyone wanting to work with the Google API in PHP should definitely check out.

I wrote a wrapper (I'll release it as a plugin if requested) for the Geocoding API, the bulk of the work (the REST call) occurs in a function called doQueryGIS.

He include the code for the wrapper function and show how to use it to make a call to the API, setting up the caching directory and passing in the raw address data from the user.

More and more people are learning about the fun sport Geocaching. Why not integrate geocaching data into your own website, creating a mashup or simply creating your own geocaching website?

PHPGeocache is a free toolkit implemented in PHP which allows everyone to integrate geocaching information into his own website. And yes, it can also be used for commercial projects.

The library allows you to grab and store geocoded data in a local database and makes it easy to pull the information out and manipulate it as you need. There's also a built in system to create paths of wyapoints for a hunt in true geocaching fashion.

In this tutorial I showed you how to submit geocoding requests via JavaScript, which is convenient because it's easy to subsequently build a map using the retrieved coordinates. However, if you're interested in performing bulk geocoding for reason of storing a series of coordinates in a database, you might be interested in taking advantage of a second means for geocoding, accomplished by way of HTTP request.

Storing the coordinates locally will not only decrease the number of required daily geocoding requests (limited to 50,000 daily), but it will speed your application by cutting down on the total requests required to ultimately build a map.

They start off with a simple example, showing how to sed the request out to Google as well as the output. They show how to get the information you need out of the return XML. This basic example leads to something more complex - the server-side caching of the geocode results in a MySQL database.

We got geocoding out of the way in the first part, so now it's time to talk distances. To figure out how far apart two places are, we could use the traditional method of calculating distances between two points, but that damn Columbus didn't fall off into the Twighlight Zone when he passed the horizon. Turns out the Earth isn't flat, go figure. Oh, and since it isn't flat, assuming that it is will cause your numbers to be off when calculating distances using normal geometry-sometimes by miles.

He links to a formula for finding the difference when the distances are short as well as a PHP implementation of the Haversine formula when the distances get long.

He combines this new knowledge with the information already obtained by the geocoding in the first part and a SQL database to help narrow down the items in the list. Then, for each of those, he compares the latitude and longitudes to get the difference between them (in miles).

Conceptually, location based searching is pretty straight-forward: find out where you are, find out how far you're willing to travel, and compare your location against the locations of all your choices. If the distance between where you are and what you're interested in is less than what you're willing to travel, add it to your results list. Simple, right? Right.

He talks more about the concepts behind the search and one of the keys to the entire process - geocoding. They opted to go with the Yahoo! Maps API to grab this information. There's some sample REST urls and the output of the results after they've been unserialized.

They've even created their own class to make things even simpler. It does require that you have cURL installed with your PHP5 installation, but outside of that, there are no other dependencies.

In the previous installment of this four-part series regarding creating spatially enabled Web applications, you learned how to create a local datasource mapping mailing addresses to latitudinal and longitudinal coordinates using the Geo::Coder::US Perl package and the U.S Census Bureau's TIGER/Line data. In this final installment, you'll learn how to make this data available to the world through a Perl-based Web service.

To demonstrate the service's capabilities, a PHP-driven client will pass a mailing address to the Web service, retrieve the spatial data made available through this Web service, and finally feed it to the Google Maps API to produce a map marking the location of the mailing address.

If you don't really know Perl all that well, don't worry too much - they give you the code you'll need to get it set up, as well as the PHP code to make the web service connection...]]> Tue, 29 Nov 2005 05:50:00 -0600